Which part? Things like the clathrate gun hypothesis, or that it will likely be hundreds of years and still a lot of effort for humanity to be done?

For the latter, I think you can take the Paleocene–Eocene Thermal Maximum as the "done" point (I don't really agree there is such a point because people already live in ridiculous conditions now, and you can protect yourself from a wet bulb event for the price of a car) and from memory under RCP 8.5 (and drilling up the arctic) the IPCC modelling put that at a couple hundred years off.